A parallel computer system including a plurality of processors is conventionally known in which the plurality of processors execute processing in parallel. For example, a parallel computer system that is connected over a network to a plurality of computers, a multiprocessor system in which a plurality of processors are connected at a bus level, and a chip multi-processor (CMP) in which a plurality of processors are integrated on the same chip are known.
These types of parallel computer systems divide one task into pieces of processing such as a plurality of processes or threads, and then allocate the divided processes or threads to the processors. In this case, the processors execute external accesses to memories, networks, and/or storages and communicate with other processors to obtain data for executing the allocated processing. The processors then use the obtained data to execute the processing, execute external accesses, and output the execution results of the processing.
Moreover, the parallel computer system waits until all the processors complete the processing. The parallel computer system then divides new tasks and allocates the divided pieces of processing to the processors when all the processors have completed the processing.
Japanese Laid-open Patent Publication No. 2000-253060 is a reference document.